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| Titel |
Vegetation fire emission coefficients derived from MODIS fire radiative power and GOME-2 tropospheric NO2 measurements |
| VerfasserIn |
Stefan Schreier, Andreas Richter, John Burrows |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250071921
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| Zusammenfassung |
| In this study, we use satellite measurements of fire radiative power (FRP) from the MODerate
resolution Imaging Spectroradiometer (MODIS) and nitrogen dioxide (NO2) from the Global
Ozone Monitoring Experiment-2 (GOME-2) to derive fire emission coefficients for different
types of vegetation. In a first step, monthly means of FRP have been analyzed for temporal
correlation with monthly means of tropospheric NO2 for five consecutive years from 2007 to
2011 on a 1° x 1° grid. The strongest correlation is largely confined to tropical and
subtropical regions which account for more than 80% of yearly burned area on average
globally. In these regions, the seasonal variation of fire intensity explained by the FRP data is
reflected by the tropospheric NO2 columns to a high degree. In a next step, spatially
averaged regression coefficients were determined for four characteristic biomass
burning regions. The obtained regression coefficients are used for the prediction of
tropospheric NO2 columns by simply applying a linear regression model. The best
agreement between estimated and observed tropospheric NO2 columns is found for the
African regions north and south of equator with large fraction of the NO2 signal
being explained by the seasonal variability of FRP. Indeed, the determination of
regression coefficients on a 1° x 1° grid highlights a spatial heterogeneity of slope
values (here referred to as fire emission coefficients) indicating changes of emission
intensity over different biomes. Therefore, a global land cover map was included in the
analysis for deriving fire emission coefficients for different types of vegetation.
Retrieved fire emission coefficients for the dominating types of vegetation burned are
0.022, 0.02, 0.019, 0.0185, 0.0131, and 0.0101 1015 molecules 10-4 mW-1 cm-2
NO2 for wooded grassland, broadleaf evergreen forest, cultivated crops, broadleaf
deciduous forest and woodland, grassland, and shrubs, respectively. However, the
precedence of these values differs amongst the four selected regions for certain vegetation
types by a factor of up to two which call into question the use of universal emission
factors in recent bottom-up emission inventories. We conclude that our calculated fire
emission coefficients may have possible implications for future efforts towards a
minimization of uncertainties in global estimates of vegetation fire NOx emissions. |
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